The endocardium lines the inner chambers of the heart. This tissue is important for the heart’s ability to pump blood efficiently throughout the body. Understanding its role is important for maintaining overall heart health.
Understanding the Endocardium
The endocardium forms the innermost layer of the heart, lining all four heart chambers: the left and right atria, and the left and right ventricles. It also extends to cover the heart valves, which regulate blood flow within the heart. This layer is composed primarily of a single sheet of endothelial cells, supported by a thin layer of connective tissue.
The smooth, thin surface of the endocardium provides a pathway for blood as it moves through the heart, minimizing turbulence and ensuring efficient circulation. Its endothelial cells produce anticoagulant factors, such as thrombomodulin and tissue factor pathway inhibitor, which help prevent blood clots from forming on the heart’s inner walls. The endocardium also acts as a protective barrier, separating the circulating blood from the underlying heart muscle, known as the myocardium.
Common Conditions Affecting the Endocardium
When the endocardium becomes inflamed, a condition called endocarditis can develop. This inflammation is often caused by bacterial or, less commonly, fungal infections. These microorganisms enter the bloodstream and then attach to damaged areas within the heart, particularly on the heart valves or other heart tissues.
While the immune system combats bacteria in the bloodstream, certain factors increase the risk of infection on the endocardium. Individuals with pre-existing heart valve damage, artificial heart valves, or certain congenital heart defects are more susceptible. Once attached, the bacteria can multiply and form growths called vegetations on the heart’s lining. These vegetations can break down surrounding heart tissue, leading to damage to the heart valves and potentially impairing their function. If left untreated, endocarditis can result in severe complications, including heart valve destruction, heart failure, stroke, or other systemic infections.
Recognizing Symptoms and Seeking Medical Attention
Symptoms of endocarditis vary and can develop gradually or suddenly. Common signs often resemble the flu and include persistent fever, chills, and night sweats. Individuals may also experience fatigue, unexplained weight loss, and body aches or joint pain.
Other indications include shortness of breath, a new or changing heart murmur (an unusual sound heard during a heartbeat), or swelling in the feet, legs, or abdomen. Less common skin manifestations include tiny red, purple, or brown spots (petechiae) on the skin, under fingernails, or on the whites of the eyes. Painful red or purple bumps on fingertips or toes (Osler nodes), or painless red or brown spots on palms or soles (Janeway lesions), can also occur. If any of these symptoms appear, especially in individuals with known heart conditions, prompt medical evaluation is necessary. Early diagnosis and treatment are important for preventing severe complications.